Discussion
Pre-operative evaluation for PVI is usually performed using TOE or CT to
assess LA/LAA and the surrounding anatomy and
thrombus1. TOE is mostly used in our institute;
however, it is time-consuming and may sometimes induce discomfort and
cause complications, and in the era of COVID-19, the indication has been
revised to prevent the spread of the virus. Cardiac CT is a reliable
alternative tool but has certain limitations in differentiating thrombi
from low blood flow and may cause serious kidney problems.
ICE is an emerging alternative for LAA assessment for patients
undergoing PVI and has similar diagnostic efficacy for LAA
thrombus2. We practically use intra-operative ICE for
AF patients with low CHADS2-Vask score ≤1: we carefully evaluate LAA
from right atrium and right ventricular outflow with ICE before the
puncture of atrial septum. The present patient had a score of 1 due to
sex alone and underwent intra-operative ICE, which revealed a small LA
myxoma attached to the atrial septum. A previous study reported that TTE
shows a high detection rate of cardiac myxoma similar to
TEE3, however, the present myxoma developing in the LA
near the fossa ovalis, the most frequent site of origin, could not be
found by TTE pre-operatively and even when we carefully examined the
images post-operatively. The presence of LA myxoma is an absolute
contraindication for PVI and the procedure was stopped before the
transseptal puncture.
Intra-procedural ICE is a reliable imaging modality when the primary aim
is to exclude LA/LAA thrombus but is unsuitable for evaluating unusual
and unexpected cardiac structures, which pre-procedural TEE or CT can
identify. Imaging options should be further discussed to improve patient
care and safety.